1987 22-2 Ospery re-power

[redemn93]

a very high percentage of boats come with the motor(s) too low from the factory.  its nothing new unfortunately.  hopefully they do you right.  best of luch with it.  you should see a nice difference in the ride and handling.  a few mph too.

[Bushleaguer]

Here's a couple of pictures.  I put a straight edge on the bottom of the main anti cav plate of the port engine.  One measurement for the inboard side, one for the outboard side.  The outer measurement is 2 1/2 inches below the hull, the inboard one is about an inch and a half.

Where the motors are mounted right now, there is only one more notch left to go up, and it will gain me about an inch.  They are going to do that this week and see what effect it has.  I would be surprised if one inch makes that much difference, but I guess we'll see.  If not, I guess we are talking jack plates??

[gran398]

Try that first...will be an improvement.

What is the distance center to center between the props?

[Bushleaguer]

Not sure- I'll have to ask them to get me that measurement- I'm an hour and a half from where the boat is.

Oh and BTW, the moving of the axles on the trailer was an easy and effective adjustment.  Perfect balance now- no trailer wagging or hull bouncing on the front rollers.

[fitz73222]

If you can only go up one more hole it sounds like the installers drilled the mounting holes too low and should have had the bolt pattern higher up on the transom. They make drill templates for this so you can get the vertical adjustment you need. Your engines need to come up at least 2" to get any real benefit. One suggestion is to have these guy's re-drill the holes higher and repair the current holes so you can get the correct amount of vertical adjustment. Your engine spacing should be 26"-27" and that will allow adequate engine clearance between them and allow you to adjust the engines up high enough relative to the deadrise change. The further the engines are apart, the higher they have to go to maintain the correct height relative to the boat bottom. I'm a little surprized they delivered this boat to you set up this way assuming they have any expertise in rigging.

[Bushleaguer]

Just got a call from the rigger.  They raised the motors up as high as they would go this morning, then took it out and test ran it.  They had two guys in the boat and were able to get 32 knots out of it in about 1.5 foot seas, so that is a noticeable improvement.  Also, the roostertail is gone as well.  I guess I'll give a try this weekend and see what it's like myself, but they claim it is better.  I'll let you know.

[fitz73222]

Well thats a 5 mph increase over where you were if I did my calculations correctly. I think you have another 2 mph if you want to to ditch those Yammi stock props and at least trade for some Merc aluminum props with a much better blade design and a decent amount of cup.

[Bushleaguer]

Maybe....  I'm really not too awful worried about the speed issue right now, at least now with the extra 5 mph.  If that roostertail stops washing into the boat and the performance is what they say it is, I think I'd be happy.  Besides, I troll a lot- that was one of my major reasons for going to twins- and I don't want too much pitch because I'd like to keep the trolling speed down as much as practical.

[fitz73222]

Just a passing comment... Whatever you do to effect top end also has a positive effect on midrange for fuel and speed. The stock Merc props with the flow torque hub for Yamaha will work much better than the stock Yamaha props and will be the same pitch as what you are running now with better bite and much more responsive to trim settings. Anyway, glad this worked out with the engine height. This is great example of how engine height has a major effect on performance. 5 mph is a considerable gain. Don't be surprised if you don't have to re-prop anyway to keep your rpms tamed.

[Bushleaguer]

Thanks for the heads up.  Your willingness to share your vast knowledge is a huge help.  

I am going up to the boat tomorrow to confirm that the performance has improved and I'll check on the RPM's.  I'm finding it a bit difficult to believe that a one inch raise on the transom had that much effect.  Hoping to give you a good report!

[Capt Matt]

I have my motor on a hydraulic lift so its totally height adjustable,  even a half inch of vertical motor lift while running on plane really effects the boats performance
I think you will be pleasantly surprised at the difference
Happy fishing
Capt Matt

[gran398]

Glad they report she's running better. However, will be interesting to see the actual amount of adjustment upwards given the last hole position.

Also interested in the measurement between the hubs. If for no other reason, to save for the archives as an executed mounting position.  We (Fitz) set up Miss D at 26.5 -27 inches center to center on the hubs.

New props are great...if the plate heights are correct or close. When you go and check her out.... take the same pic of the straightedge to the hull off the cav plates, let's see where they are.

Mine were 3/8ths deep across the board.  They say 1/4 shallow is better.

But she is running real good. As Matt advises.... a little goes a long way at speed.

[Bushleaguer]

I went up to check everything out last night.  First off, there is total miscommunication on the speed.  My readings with the old motor (top speed 26 knots) and the new twins before being raised (27.7 knots) were GPS speed in nautical MPH.  The 32 MPH figure given to me over the phone by the dealer were statute MPH off the boat's gauges.  So the speed increase was negligible based on the info I got over the phone.

However, I put her in last night and put a good 2 1/2 hours on it.  There is a marked improvement.  There is no longer a rooster tail that flows right over the transom at high speeds.  Water flows under the boat at planning speed like it should.  The boat now responds to motor trim much better- before, I could run them in the fully down position and that was pretty much it.  Now, the attitude gets adjusted effectively when you trim them.

Actual top speed when trimmed out, flat lake, me in the boat alone with a full fuel load is 29.9 knots.  No matter what I did, I couldn't squeeze out that last tenth to get 30.  RPM's now are up to 6200 at WOT.  I re-measured the cav plate in relation to the hull.  I seem to have gained only 3/4".  Pics follow.  Also there is a decent close-up shot of the port engine viewed from behind the boat that shows where the motors currently are.  

The dimension between the props, center to center is 28 1/4".  The center of the engines are 14 1/4" from the centerline of the keel.

 






I suspect that the engines are too far apart, and too far from the center line.  I'm trying to decide if I should just live with it the way it is for now (the top speed thing really doesn't bother me- the fact that the hole shot / low end torque is outstanding is more important- and fantastic with the new setup) or go back and demand that the remove the motors, patch the holes, and start over.

[gran398]

You are right, they are still too low. She should be making in the upper 30's WOT. The reason she's not is due to excessive drag.

This will also adversely effect your fuel economy. You will have to turn excessive RPM's to make the same speed versus lower RPM's if the install were correct.

Certainly not trying to tell you what to do, but I'd take it back. Hang them at twenty six inches apart. This is their goof, not yours. If they try and charge you tell them they effed up. Which they did.

If you wait, it is just more ammunition for them to hang a re-rigging charge on you.

Know this is a PITA, but you have some serious money invested here...it needs to be right, especially if you ever try to sell it.

Good luck! Keep us posted.

[Blue Agave]

^^^What Gran said. Those motors are to low and from what I can see from the photos the mounting bolts are already at the top of the transom. Your only recourse is to move each motor inboard 1 1/8, that we give you 26" centers.